As is well known, various types of devices have been heretofore suggested and/or developed for monitoring or warning of selected conditions. From the standpoint of danger or potential harm, an important condition to be monitored is that of combustion, particularly in buildings or other structures where early detection of the presence of fire is essential to protect both life and property.
Combustion detection devices have been heretofore suggested and/or utilized and such devices using ionization chambers for detection purposes have heretofore been battery operated as well as operating from a conventional A.C. source. Examples of battery operated smoke detectors can be found, for example, in U.S. Pat. Nos. 3,717,862, 3,778,800 and 4,004,288, while example of smoke detectors utilizing a conventional commercial power source can be found in U.S. Pat. Nos. 3,842,409 and 3,866,195.
Improvements in detectors having ionization chambers for smoke detection can be realized, however, by providing a more efficient chamber which could result, for example, in a lower requirement for the amount of the radioactive source that might be utilized, and/or more simplified but yet dependable electronic circuitry to be utilized in conjunction with the chamber.